#ifndef __MD5__
#define __MD5__

namespace md5
{
	typedef struct 
	{
		uint32_t	i[2];			/* number of _bits_ handled mod 2^64 */
		uint32_t	buf[4];			/* scratch buffer */
		uint8_t		in[64];			/* input buffer */
		uint8_t		digest[16];		/* actual digest after MD5Final call */
	} MD5_CTX;

	/* forward declaration */
	static void Transform (uint32_t *buf, uint32_t *in);

	static const uint8_t PADDING[64] = {
	  0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
	  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
	};

	/* F, G, H and I are basic MD5 functions */
	#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
	#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
	#define H(x, y, z) ((x) ^ (y) ^ (z))
	#define I(x, y, z) ((y) ^ ((x) | (~z)))

	/* ROTATE_LEFT rotates x left n bits */
	#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))

	/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4 */
	/* Rotation is separate from addition to prevent recomputation */
	#define FF(a, b, c, d, x, s, ac) \
	  {(a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
	   (a) = ROTATE_LEFT ((a), (s)); \
	   (a) += (b); \
	  }
	#define GG(a, b, c, d, x, s, ac) \
	  {(a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
	   (a) = ROTATE_LEFT ((a), (s)); \
	   (a) += (b); \
	  }
	#define HH(a, b, c, d, x, s, ac) \
	  {(a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
	   (a) = ROTATE_LEFT ((a), (s)); \
	   (a) += (b); \
	  }
	#define II(a, b, c, d, x, s, ac) \
	  {(a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
	   (a) = ROTATE_LEFT ((a), (s)); \
	   (a) += (b); \
	  }

	#ifdef __STDC__
	#define UL(x) x##UL
	#else
	#ifdef WIN32
	#define UL(x) x##UL
	#else
	#define UL(x) x
	#endif
	#endif

	static void MD5Init (MD5_CTX *mdContext)
	{
	  mdContext->i[0] = mdContext->i[1] = (uint32_t)0;

	  /* Load magic initialization constants. */
	  mdContext->buf[0] = (uint32_t)0x67452301UL;
	  mdContext->buf[1] = (uint32_t)0xefcdab89UL;
	  mdContext->buf[2] = (uint32_t)0x98badcfeUL;
	  mdContext->buf[3] = (uint32_t)0x10325476UL;
	}

	static void MD5Update(MD5_CTX *mdContext, const uint8_t *inBuf, size_t inLen)
	{
	  uint32_t in[16];
	  int mdi;
	  size_t i, ii;
  
	  /* compute number of bytes mod 64 */
	  mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	  /* update number of bits */
	  if ((mdContext->i[0] + ((uint32_t)inLen << 3)) < mdContext->i[0]) {
		mdContext->i[1]++;
	  }
	  mdContext->i[0] += ((uint32_t)inLen << 3);
	  mdContext->i[1] += ((uint32_t)inLen >> 29);

	  while (inLen--) {
		/* add new character to buffer, increment mdi */
		mdContext->in[mdi++] = *inBuf++;

		/* transform if necessary */
		if (mdi == 0x40) {
		  for (i = 0, ii = 0; i < 16; i++, ii += 4) {
			in[i] = (((uint32_t)mdContext->in[ii+3]) << 24) |
					(((uint32_t)mdContext->in[ii+2]) << 16) |
					(((uint32_t)mdContext->in[ii+1]) << 8)  |
					((uint32_t)mdContext->in[ii]);
		  }
		  Transform (mdContext->buf, in);
		  mdi = 0;
		}
	  }
	}

	static void MD5Final(uint8_t* hash, MD5_CTX *mdContext)
	{
	  uint32_t in[16];
	  int mdi;
	  size_t i, ii;
	  size_t padLen;

	  /* save number of bits */
	  in[14] = mdContext->i[0];
	  in[15] = mdContext->i[1];

	  /* compute number of bytes mod 64 */
	  mdi = (int)((mdContext->i[0] >> 3) & 0x3F);

	  /* pad out to 56 mod 64 */
	  padLen = (mdi < 56) ? (56 - mdi) : (120 - mdi);
	  MD5Update (mdContext, PADDING, padLen);

	  /* append length in bits and transform */
	  for (i = 0, ii = 0; i < 14; i++, ii += 4) {
		in[i] = (((uint32_t)mdContext->in[ii+3]) << 24) |
				(((uint32_t)mdContext->in[ii+2]) << 16) |
				(((uint32_t)mdContext->in[ii+1]) << 8)  |
				((uint32_t)mdContext->in[ii]);
	  }
	  Transform (mdContext->buf, in);

	  /* store buffer in digest */
	  for (i = 0, ii = 0; i < 4; i++, ii += 4) {
		mdContext->digest[ii]   = (uint8_t)(mdContext->buf[i] & 0xFF);
		mdContext->digest[ii+1] =
		  (uint8_t)((mdContext->buf[i] >> 8)  & 0xFF);
		mdContext->digest[ii+2] =
		  (uint8_t)((mdContext->buf[i] >> 16) & 0xFF);
		mdContext->digest[ii+3] =
		  (uint8_t)((mdContext->buf[i] >> 24) & 0xFF);
	  }
	  memcpy(hash, mdContext->digest, 16);
	}

	static void Transform (uint32_t *buf, uint32_t *in)
	{
	  uint32_t a = buf[0], b = buf[1], c = buf[2], d = buf[3];

	  /* Round 1 */
	#define S11 7
	#define S12 12
	#define S13 17
	#define S14 22
	  FF ( a, b, c, d, in[ 0], S11, UL(3614090360)); /* 1 */
	  FF ( d, a, b, c, in[ 1], S12, UL(3905402710)); /* 2 */
	  FF ( c, d, a, b, in[ 2], S13, UL( 606105819)); /* 3 */
	  FF ( b, c, d, a, in[ 3], S14, UL(3250441966)); /* 4 */
	  FF ( a, b, c, d, in[ 4], S11, UL(4118548399)); /* 5 */
	  FF ( d, a, b, c, in[ 5], S12, UL(1200080426)); /* 6 */
	  FF ( c, d, a, b, in[ 6], S13, UL(2821735955)); /* 7 */
	  FF ( b, c, d, a, in[ 7], S14, UL(4249261313)); /* 8 */
	  FF ( a, b, c, d, in[ 8], S11, UL(1770035416)); /* 9 */
	  FF ( d, a, b, c, in[ 9], S12, UL(2336552879)); /* 10 */
	  FF ( c, d, a, b, in[10], S13, UL(4294925233)); /* 11 */
	  FF ( b, c, d, a, in[11], S14, UL(2304563134)); /* 12 */
	  FF ( a, b, c, d, in[12], S11, UL(1804603682)); /* 13 */
	  FF ( d, a, b, c, in[13], S12, UL(4254626195)); /* 14 */
	  FF ( c, d, a, b, in[14], S13, UL(2792965006)); /* 15 */
	  FF ( b, c, d, a, in[15], S14, UL(1236535329)); /* 16 */

	  /* Round 2 */
	#define S21 5
	#define S22 9
	#define S23 14
	#define S24 20
	  GG ( a, b, c, d, in[ 1], S21, UL(4129170786)); /* 17 */
	  GG ( d, a, b, c, in[ 6], S22, UL(3225465664)); /* 18 */
	  GG ( c, d, a, b, in[11], S23, UL( 643717713)); /* 19 */
	  GG ( b, c, d, a, in[ 0], S24, UL(3921069994)); /* 20 */
	  GG ( a, b, c, d, in[ 5], S21, UL(3593408605)); /* 21 */
	  GG ( d, a, b, c, in[10], S22, UL(  38016083)); /* 22 */
	  GG ( c, d, a, b, in[15], S23, UL(3634488961)); /* 23 */
	  GG ( b, c, d, a, in[ 4], S24, UL(3889429448)); /* 24 */
	  GG ( a, b, c, d, in[ 9], S21, UL( 568446438)); /* 25 */
	  GG ( d, a, b, c, in[14], S22, UL(3275163606)); /* 26 */
	  GG ( c, d, a, b, in[ 3], S23, UL(4107603335)); /* 27 */
	  GG ( b, c, d, a, in[ 8], S24, UL(1163531501)); /* 28 */
	  GG ( a, b, c, d, in[13], S21, UL(2850285829)); /* 29 */
	  GG ( d, a, b, c, in[ 2], S22, UL(4243563512)); /* 30 */
	  GG ( c, d, a, b, in[ 7], S23, UL(1735328473)); /* 31 */
	  GG ( b, c, d, a, in[12], S24, UL(2368359562)); /* 32 */

	  /* Round 3 */
	#define S31 4
	#define S32 11
	#define S33 16
	#define S34 23
	  HH ( a, b, c, d, in[ 5], S31, UL(4294588738)); /* 33 */
	  HH ( d, a, b, c, in[ 8], S32, UL(2272392833)); /* 34 */
	  HH ( c, d, a, b, in[11], S33, UL(1839030562)); /* 35 */
	  HH ( b, c, d, a, in[14], S34, UL(4259657740)); /* 36 */
	  HH ( a, b, c, d, in[ 1], S31, UL(2763975236)); /* 37 */
	  HH ( d, a, b, c, in[ 4], S32, UL(1272893353)); /* 38 */
	  HH ( c, d, a, b, in[ 7], S33, UL(4139469664)); /* 39 */
	  HH ( b, c, d, a, in[10], S34, UL(3200236656)); /* 40 */
	  HH ( a, b, c, d, in[13], S31, UL( 681279174)); /* 41 */
	  HH ( d, a, b, c, in[ 0], S32, UL(3936430074)); /* 42 */
	  HH ( c, d, a, b, in[ 3], S33, UL(3572445317)); /* 43 */
	  HH ( b, c, d, a, in[ 6], S34, UL(  76029189)); /* 44 */
	  HH ( a, b, c, d, in[ 9], S31, UL(3654602809)); /* 45 */
	  HH ( d, a, b, c, in[12], S32, UL(3873151461)); /* 46 */
	  HH ( c, d, a, b, in[15], S33, UL( 530742520)); /* 47 */
	  HH ( b, c, d, a, in[ 2], S34, UL(3299628645)); /* 48 */

	  /* Round 4 */
	#define S41 6
	#define S42 10
	#define S43 15
	#define S44 21
	  II ( a, b, c, d, in[ 0], S41, UL(4096336452)); /* 49 */
	  II ( d, a, b, c, in[ 7], S42, UL(1126891415)); /* 50 */
	  II ( c, d, a, b, in[14], S43, UL(2878612391)); /* 51 */
	  II ( b, c, d, a, in[ 5], S44, UL(4237533241)); /* 52 */
	  II ( a, b, c, d, in[12], S41, UL(1700485571)); /* 53 */
	  II ( d, a, b, c, in[ 3], S42, UL(2399980690)); /* 54 */
	  II ( c, d, a, b, in[10], S43, UL(4293915773)); /* 55 */
	  II ( b, c, d, a, in[ 1], S44, UL(2240044497)); /* 56 */
	  II ( a, b, c, d, in[ 8], S41, UL(1873313359)); /* 57 */
	  II ( d, a, b, c, in[15], S42, UL(4264355552)); /* 58 */
	  II ( c, d, a, b, in[ 6], S43, UL(2734768916)); /* 59 */
	  II ( b, c, d, a, in[13], S44, UL(1309151649)); /* 60 */
	  II ( a, b, c, d, in[ 4], S41, UL(4149444226)); /* 61 */
	  II ( d, a, b, c, in[11], S42, UL(3174756917)); /* 62 */
	  II ( c, d, a, b, in[ 2], S43, UL( 718787259)); /* 63 */
	  II ( b, c, d, a, in[ 9], S44, UL(3951481745)); /* 64 */

	  buf[0] += a;
	  buf[1] += b;
	  buf[2] += c;
	  buf[3] += d;
	}

#undef F
#undef G
#undef H
#undef I
#undef ROTATE_LEFT
#undef FF
#undef GG
#undef HH
#undef II
#undef UL
#undef S11
#undef S12
#undef S13
#undef S14
#undef S21
#undef S22
#undef S23
#undef S24
#undef S31
#undef S32
#undef S33
#undef S34
#undef S41
#undef S42
#undef S43
#undef S44


};

#endif
